Guys, I asked this guy for his number and he's 18 and we've been talking im younger than him and I don't know how to tell if he likes me help plz?

i asked him if my age was a problem and he said its not he talks to anyone he's friendly... he said that im cute though with a heart emoji... i really want to get in a relationship with him but im scared that he doesn't want one with a younger girl (im 15)